Season beef with salt and pepper and brown in oil in batches.
Cook shallots, garlic, and bacon in the same pan, then transfer to the casserole with herbs.
Preheat the oven to 180°C.
Deglaze the pan with stout, add stock, and bake for 1.5 to 2 hours until tender.
Stir in cornflour paste, simmer on the hob until thickened, and leave to cool.
Increase oven to 200°C and prepare pastry by grating butter into salted flour with water.
Line the dish with rolled pastry, add beef filling and oysters, and apply egg wash to edges.
Cover with a pastry lid, seal edges, glaze with egg, and bake for 25 to 30 minutes at 200°C.